Fe3O4:Ce thin films were deposited on glass and Si substrates by Pulse Laser Deposition Technique (PLD). Polycrystalline nature of the cubic structure with the preferred orientation of (311) are proved by X-ray diffraction. The nano size of the prepared films are revealed by SEM measurement. Undoped Iron oxide and doped with different concentration of Ce films have direct allowed transition band gap with 2.15±0.1 eV which is confirmed by PL Photoluminescence measurements. The PL spectra consist of the emission band located at two sets of peaks, set (A) at 579±2 nm , and set (B) at 650 nm, respectively when it is excited at an excitation wavelength of 280 nm at room temperature. I-V characteristics have been studied in the dark and under various illuminations intensities. Ideality factor, barrier height and saturation current have been calculated in the dark. Photocurrent, gain and sensitivity have been measured under illuminations with halogen lamp with different intensities. Fe3O4:Ce thin films have been used in photoconductive applications, many wavelengths have been used; 373, 395, 445, 475, 540, 935 nm. Sensitivity, rise and fall times have been calculated for these wavelengths. In general the results revealed fast rise and fall times which is~ ms with more than 1000% sensitivity for 935 nm
The work in this paper focuses on the system quality of direct and coherent communication system for two computers. A system quality is represented by Signal to Noise ratio (SNR) and Bit Error Rate (BER). First part of the work includes implementation of direct optical fiber communication system and measure the system quality .The second part of the work include implementation both the( homodyne and heterodyne)coherent optical fiber communication system and measure the system quality . Laser diode 1310 nm wavelength with its drive circuit used in the transmitter circuit . A single mode of 62.11 km optical fiber is selected as transmission medium . A PIN photo detector is used in the receiver circuit. The optical D-coupler was u
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This work represents implementation and investigation of optical coherent communication system between two computers. A single mode optical fiber is selected as transmission medium. The data are sent via the RS-232 standard interface with a bit rate of 9.6 kbps from personal computer (PC1) by line receive to convert the data from electrical levels (-12/+12 V) into TTL level (0/5 V). The modulation of this data was accomplished by internal modulation using laser diode type (HFCT-5208M) 1310 nm wavelength. The optical D-coupler was used to combine the optical signal that come from laser source with optical signal of laser local oscillator (OTS-304XI) at 1310/1550 nm wavelength to obtain coherent (homodyne and heterodyne) detection respective
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The Indian costus plasma properties are investigated including electron temperature (Te), "electron density (ne)", "plasma frequency (fp)", " Debye sphere length", and amount of Debye(Nd), using the spectrum of optical emission technique. There are several energies used, with ranging from 300 to 600 mJ. The Boltzmann Plot is used to calculate the temperature; where as Stark's Line Broadening is used to calculate the electron density. The Indian costus was spectroscopically examined in the air with the laser at 10 cm away from the target and the optical fiber at 0.5 cm away. The results were obtained for an electron temperature range of (1.8-2.2) electron volts (ev) and a wavelength range of (300-600) nm. The XRF analysis reveals th
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In the present work, the effect of size of zinc dust particles on
AC argon discharge characteristics are investigated
experimentally. The plasma characteristics are determined by
using optical emission spectroscopy (OES) techniques. The
results illustrated that the electron temperature (Te) in the present
and absent of Zinc dust particle is reduced with increasing of
pressure. The electron temperature decreases with increasing of
Zinc dust size. Excitation temperature Tex is reduces with
increasing of Ar pressure in present and absent of zinc dust
particles. The present of Zinc dust reduce the Tex of Ar in both
Zinc dust size. The electron density increasing in the present and
absent of both zinc dust siz
The characteristics of atmospheric-pressure glow discharge (APGD) produced by rod-plate electrodes are experimentally determined. APGD is sustained by applying a high DC voltage between the electrodes. At atmospheric pressure, the shift from corona discharge to glow discharge is investigated. A rod-plate discharges configuration's volt–ampere properties show the existence of three discharge regimes: corona, glow, and spark. The variations in the electrical field distribution in the various regimes are mirrored in the discharge luminosity. The rod-plate patterns are created under a dark region, and are visible mainly due to the effect of electrons heated by the local enhanced electric field at the interface, according to the op
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This study uses the optical emission spectroscopy (OES) technique to find the lead(Pb) and sulfur (S) plasma parameters employing a pulse of Nd: YAG laser (Q-switched 1064nm wavelength) and different laser energies of (400,500,600 and 700 mJ). The electron temperature Te (eV) is calculated using the Boltzmann-Plot method, and the electron density ne (cm-3)is determined by the Stark broadened way. Moreover, Debye length λD (cm) and plasma frequency ωp (Hz) are studied as a function of laser energy. An apparent increase was noted in the electron temperature of lead plasma and a decrease in sulfur plasma. The results also showed that each increase in the laser intensity causes an incr
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Abstract
In this work, the plasma parameters (electron temperature (Te), electron density( ne), plasma frequency (fp) and Debye length (λD)) have been studied by using the spectrometer that collect the spectrum of Laser produce CdTe(X):S(1-X) plasma at X=0.5 with different energies. The results of electron temperature for CdTe range 0.758-0.768 eV also the electron density 3.648 1018 – 4.560 1018 cm-3 have been measured under vacuum reaching 2.5 10-2 mbar .Optical properties of CdTe:S were determined through the optical transmission method using ultraviolet visible spectrophotometer within the r
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Abstract: This paper presents the results of the structural and optical analysis of CdS thin films prepared by Spray of Pyrolysis (SP) technique. The deposited CdS films were characterized using spectrophotometer and the effect of Sulfide on the structural properties of the films was investigated through the analysis of X-ray diffraction pattern (XRD). The growth of crystal became stronger and more oriented as seen in the X-ray diffraction pattern. The studying of X-ray diffraction showed that; all the films have the hexagonal structure with lattice constants a=b=4.1358 and c=6.7156A°, the crystallite size of the CdS thin films increases and strain (ε) as well as the dislocation density (δ) decreases. Also, the optical properties of the
... Show MoreThe present paper analyzes the signal emitting from the Reticle during changing the spot size of laser falling on the disk and shows the optimum frequency and the amount of energy window in different patterns of modulator (Reticle). All results are obtained by establishing a special program named “Disk optical modulator version 3" using the language visual basic 6 ahich contains many parameters. All models of optical modulator consist of twenty sectors, ten sectors are opaque and other ten sectors are transmitted for the laser. The number of sectors depends on several factors as chopping frequency, power transparent and modulation transfer function. It has been demonstrated by simulations, the optimal
... Show MoreIn this work, the optical emission spectrum technique was used to analyze the spectrum resulting from the CdO:Sn plasma produced by laser Nd:YAG with a wavelength of (1064) nm, duration of (9) ns, and a focal length of (10) cm in the range of energy of 500-800 mJ. The electron temperature (Te) was calculated using the in ratio line intensities method, while the electron density (ne) was calculated using Saha-Boltzmann equation. Also, other plasma parameters were calculated, such as plasma (fp), Debye length (λD) and Debye number (ND). At mixing ratios of X=0.1, 0.3 and 0.5, the CdO1-X :SnX plasma spectrum was recorded for different energies. The change
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